Locking device



NGV. C. S. BROWN LOCKING DEVICE Filed May l2 1922 2 Sheets-Sheet l www fw:

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afronta New. 3 E923.. x LAE-7399@ c. s. BROWN LOCKING DEVICE Filed May l2, 1922 2 Sheets-Sheet 2 @atented Nov. 133, 1923.

hillvt@ STATES CHALMERS BRWN, F LIMA, OHO.

BOOKING DEVICE.

Application led May 12,

` position.

ln the present invention, 1 provide a pivoted latch arranged beneath the man hole cover and adapted to engage a shoulder on the frame. The latch is designed to normally assume locked position and is provided w'ith a control member pivoted adjacent thereto. The latch is released by lifting the tree end of the control member and this member is provided with a recess adapted to` receive a tooth carried by thc latch whereby the movement of the latch is limited by the control member and it is always retained inposition to engage a portion of the frame when the man hole cover is inserted; l

In the accompanying drawings, l have shown one embodiment ot the invention. In this showing: i

Figure 1 is a plan view.

Figure 2 is a vertical sectional view.

Figure 3 is a detailsectional view of the cover, showing the locking mem-ber in elevation.

Figure Si is a perspective view of the locking member removed, and,

Figure 5 is a detail view of a key.

Referring to the drawings, the reference numeral 1 designates a man hole frame and 2 a man holecover. As shown, the trame is provided with an enlarged annular portion 3 forming a'seat 4 for the cover. The lower face of 'the enlargement forms a shoulder 5.

The locking device forming the subject matter of the present invention is arranged on theI under side of the cover and is adapted to engage the shoulder 5. Any numbe x of lookin devices may be employed. 1n the present instance, 1 have shown a cover provided with a pair of locking devices. As the construction ot the locking 1922. Serial No. 560,402.

devices is identical, a description of one will suffice. The cover is provided with a pair of downwardly projecting arms 6, forming supports for the latch' and control member. As shown, the latch consists ot a member having an opening 8 therein for the reception ort a ivot pin 9 passing through suit# able openings in the arms 6 and arranged adjacent the bottom. The latch is provided with a locking face 10 and is so arranged that it normally tends to swing outwardly toward the trame. 1t is further provided with a tooth 11 projecting 'from its upper' face. A control member 12 is arranged above the latch and pivotally mounted in the arms 6. As shown, this member is provided with an opening 13, adjacent one end tor the reception of a pivot pin 1a. lt will be apparent that the tendency ot' the Control member is to swing downwardly to the position shown in Figure 2 of the drawings, and this tendency is increased by providing the free end of the control member with an enlargement 14. The lower face of the control member is provided with a recess 15, for the reception of a key. The cover is provided with suitable slots 16 adjacent each ot the lockino members for the insertion of the key. s shown, the key'consists of a rod 17 having a hook 18 formed on its lower end. The key may be provided with a suitable handle portion 19.

1n operation, the tooth 11 is normally received in a recess 2O formed in the lower face ot" the control member. The latch is provided with the greater portion of its weight on the outside of the pivot and tends to swin outwardly rlhis outward swlnging is mited by 'the arrangement of the tooth Within the recess and the latch is preengage the hook 18 in the recess 15 ot` the.

control member. The control member is then lifted to the dotted line position shown in Figure 2 of the drawings and the latch is swung to inoperative position by the engagement ofthe tooth 11 in the recess 20. inserting a pair of keys and lifting the control members, the cover is unlocked and it. y then be removed by further lifting of the keys and the cover. By providing a control member pivoted as shown, and arranged beneath theJ cover, the movement of the latch is limited to a small are and it is prevented from swinging downwardly to an inoperative position. It will be apparent that when the cover is removed, the latch would have a tendency to assume a position depending from the arms 6 and thus be inoperative were its movement not limited by the control member.

It is to be understood that the form of my invention herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangement of parts may be resorted to without .departing .from the spirit of the invention'or the scope of the subjoined claims.

Having thus described my invention, I claim:

1. A locking device for man hole covers comprising a latch pivoted to said cover and adapted to swing outwardly vby gravity, and a control member engaging said latch to limit its outward movement and retain it in an operative position.

2. A locking device for man hole covers comprising a latch pivoted to said cover and adapted to swing outwardly, and a pivotally mounted control member arranged above said latch and adapted to engage it to limit its outward movement.

3. A locking device for man hole covers comprising a latch pivoted thereto .and

adapted to swing outwardly, the 'free end of said latch being provided with a tooth, and a pivotally mounted control member arranged adjacent said latch, said control member being provided with a recess adapted to receive said tooth to limit the movement of said latch.

4. A locking device for man hole covers comprising a pair of arms depending from said cover, a latching member pivotally mounted in the lower portion off said arms, said member extending upwardly and outwardly, and a control member pivotally mounted in ythe upper portion of said arms, said control member being adapted to engage said locking member to retain it in operative position.

5. A locking device for man hole covers comprising a pair of arms depending from said cover. a latch pivotally mounted in the lower portion of said arms, said latch eX- tending upwardly and outwardly and being provided with a tooth on its upper end, and a control' member pivotally mounted in said arms above said latch, said control member being provided with a recess for the reception of said tooth.

In testimony whereof I aix my signature in presence of two witnesses.

CHALMERS S. BROWN.

Witnesses:

FRED BISZANTZ, 

